/*
 * jPOS Project [http://jpos.org]
 * Copyright (C) 2000-2015 Alejandro P. Revilla
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.jpos.tlv.packager.bertlv;


import org.jpos.emv.UnknownTagNumberException;
import org.jpos.iso.*;
import org.jpos.iso.packager.GenericPackager;
import org.jpos.tlv.ISOTaggedField;
import org.jpos.tlv.TLVDataFormat;
import org.jpos.util.LogEvent;
import org.jpos.util.Logger;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;


/**
 * Packager for ISO 8825 BER TLV values.
 *
 * @author Vishnu Pillai
 */

public abstract class BERTLVPackager extends GenericPackager {

	private static final int MAX_LENGTH_BYTES = 5;
	private static final int MAX_TAG_BYTES = 2;

	private static final LiteralInterpreter literalInterpreter = LiteralInterpreter.INSTANCE;
	private static final AsciiInterpreter asciiInterpreter = AsciiInterpreter.INSTANCE;
	private static final BCDInterpreter bcdInterpreterLeftPaddedZero = BCDInterpreter.LEFT_PADDED;
	private static final BCDInterpreter bcdInterpreterRightPaddedF = BCDInterpreter.RIGHT_PADDED_F;

	private final BinaryInterpreter tagInterpreter;
	private final BinaryInterpreter lengthInterpreter;
	private final BinaryInterpreter valueInterpreter;


	public BERTLVPackager() throws ISOException {
		super();
		tagInterpreter = getTagInterpreter();
		lengthInterpreter = getLengthInterpreter();
		valueInterpreter = getValueInterpreter();
	}

	protected abstract BinaryInterpreter getTagInterpreter();

	protected abstract BinaryInterpreter getLengthInterpreter();

	protected abstract BinaryInterpreter getValueInterpreter();

	protected abstract BERTLVFormatMapper getTagFormatMapper();

	/**
	 * Pack the sub-field into a byte array
	 */
	public byte[] pack(ISOComponent m) throws ISOException {
		return pack(m, false, getFirstField(), m.getMaxField());
	}

	public byte[] pack(ISOComponent m, boolean nested, int startIdx, int endIdx)
			throws ISOException {
		LogEvent evt = new LogEvent(this, "pack");
		try {
			ISOComponent c;
			List<byte[]> l = new ArrayList<byte[]>();
			Map fields = m.getChildren();
			int len = 0;
			for (int i = startIdx; i <= endIdx; i++) {
				c = (ISOComponent) fields.get(i);
				if (c != null) {
					try {
						final byte[] b;
						if (c instanceof ISOTaggedField) {
							b = packTLV((ISOTaggedField) c);
						} else {

							if (c.getValue() == null) {
								b = new byte[0];
							} else if (!nested && (i == startIdx || i == endIdx) &&
									this.fld.length > i && this.fld[i] != null) {
								b = this.fld[i].pack(c);
							} else {
								throw new ISOException(
										"Field: " +
												i +
												" of type: " +
												c.getClass() +
												" cannot be packed. Either the object should be of type ISOTagField" +
												" OR this should be the first or last sub-field and a packager" +
												" should be configured for the same");
							}
						}
						len += b.length;
						l.add(b);
					} catch (Exception e) {
						evt.addMessage("error packing sub-field " + i);
						evt.addMessage(c);
						evt.addMessage(e);
						throw e;
					}
				}
			}
			int k = 0;
			byte[] d = new byte[len];
			for (byte[] b : l) {
				System.arraycopy(b, 0, d, k, b.length);
				k += b.length;
			}
			if (logger != null) // save a few CPU cycle if no logger available
				evt.addMessage(ISOUtil.hexString(d));
			return d;
		} catch (ISOException e) {
			evt.addMessage(e);
			throw e;
		} catch (Exception e) {
			evt.addMessage(e);
			throw new ISOException(e);
		} finally {
			Logger.log(evt);
		}
	}

	private byte[] packTLV(ISOTaggedField c) throws ISOException {
		byte[] b;
		final byte[] rawValueBytes;

		try {
			rawValueBytes = packValue(c.getTag(), c);
		} catch (UnknownTagNumberException e) {
			throw new ISOException(e);
		}

		byte[] valueBytes = new byte[valueInterpreter.getPackedLength(rawValueBytes.length)];
		valueInterpreter.interpret(rawValueBytes, valueBytes, 0);

		byte[] tagBytes = packTag(c);
		byte[] lengthBytes = packLength(valueBytes);

		b = new byte[tagBytes.length + lengthBytes.length + valueBytes.length];
		System.arraycopy(tagBytes, 0, b, 0, tagBytes.length);
		System.arraycopy(lengthBytes, 0, b, tagBytes.length, lengthBytes.length);
		System.arraycopy(valueBytes, 0, b, tagBytes.length + lengthBytes.length, valueBytes.length);
		return b;
	}

	private byte[] packTag(final ISOTaggedField c) {
		final byte[] tagBytes;
		String tag = c.getTag();
		tagBytes = ISOUtil.hex2byte(tag);
		byte[] packedTagBytes = new byte[tagInterpreter.getPackedLength(tagBytes.length)];
		tagInterpreter.interpret(tagBytes, packedTagBytes, 0);
		return packedTagBytes;
	}

	private byte[] packLength(final byte[] valueBytes) {
		final byte[] lengthBytes;
		int length = valueBytes.length;
		if (length > 0x7F) {
			byte[] lengthBytesSuffix = ISOUtil.int2byte(length);
			lengthBytes = new byte[lengthBytesSuffix.length + 1];
			lengthBytes[0] = (byte) (0x80 | lengthBytesSuffix.length);
			System.arraycopy(lengthBytesSuffix, 0, lengthBytes, 1, lengthBytesSuffix.length);
		} else {
			lengthBytes = new byte[]{(byte) length};
		}
		byte[] packedLengthBytes = new byte[lengthInterpreter.getPackedLength(lengthBytes.length)];
		lengthInterpreter.interpret(lengthBytes, packedLengthBytes, 0);
		return packedLengthBytes;

	}

	@Override
	public int unpack(ISOComponent m, byte[] b) throws ISOException {
		try {
			return unpack(m, b, false);
		} catch (RuntimeException e) {
			throw new ISOException(e);
		}
	}

	public int unpack(ISOComponent m, byte[] b, boolean nested) throws ISOException {
		LogEvent evt = new LogEvent(this, "unpack");
		try {
			if (m.getComposite() == null)
				throw new ISOException("Can't call packager on non Composite");
			if (b.length == 0)
				return 0; // nothing to do
			if (logger != null) // save a few CPU cycle if no logger available
				evt.addMessage(ISOUtil.hexString(b));

			int tlvDataLength = b.length;

			int consumed = 0;
			int subFieldNumber = 1;
			if (!nested && fld.length > 1) {
				ISOFieldPackager packager = fld[1];
				if (packager != null) {
					ISOComponent subField = packager.createComponent(1);
					consumed = consumed + packager.unpack(subField, b, consumed);
					m.set(subField);
				}
				subFieldNumber++;
			}

			while (consumed < tlvDataLength) {
				ISOFieldPackager packager;
				if (!nested && fld.length > 1 && (packager = fld[fld.length - 1]) != null &&
						packager.getLength() == tlvDataLength - consumed) {
					ISOComponent subField = packager.createComponent(fld.length - 1);
					consumed = consumed + packager.unpack(subField, b, consumed);
					m.set(subField);
					subFieldNumber++;
				} else {
					//Read the Tag per BER
					UnpackResult tagUnpackResult = unpackTag(b, consumed);
					consumed = consumed + tagUnpackResult.consumed;
					final byte[] tagBytes = tagUnpackResult.value;
					String tag = ISOUtil.byte2hex(tagBytes).toUpperCase();
					UnpackResult lengthUnpackResult = unpackLength(b, consumed);
					consumed = consumed + lengthUnpackResult.consumed;
					int length = ISOUtil.byte2int(lengthUnpackResult.value);

					final ISOComponent tlvSubFieldData;
					byte[] value = new byte[length];

					if (length > 0) {
						System.arraycopy(b, consumed, value, 0, value.length);
					}

					int uninterpretLength = getUninterpretLength(length, valueInterpreter);
					byte[] rawValueBytes =
							valueInterpreter.uninterpret(value, 0, uninterpretLength);

					tlvSubFieldData = unpackValue(tag, rawValueBytes, subFieldNumber, length);


					consumed = consumed + length;
					ISOTaggedField tlv = new ISOTaggedField(tag, tlvSubFieldData);
					m.set(tlv);
					subFieldNumber++;
				}
			}
			if (b.length != consumed) {
				evt.addMessage("WARNING: unpack len=" + b.length + " consumed=" + consumed);
			}
			return consumed;
		} catch (ISOException e) {
			evt.addMessage(e);
			throw e;
		} catch (Exception e) {
			evt.addMessage(e);
			throw new ISOException(e);
		} finally {
			Logger.log(evt);
		}
	}

	private UnpackResult unpackTag(final byte[] tlvData, final int offset) {
		byte[] tlvBytesHex =
				tagInterpreter.uninterpret(
						tlvData,
						offset,
						tlvData.length >= offset + MAX_TAG_BYTES
								? MAX_TAG_BYTES : tlvData.length - offset);
		int index = 0;
		final byte[] tagBytes;
		byte tagByte = tlvBytesHex[index];
		int tagLength = 1;
		if ((tagByte & 0x1F) == 0x1F) {
			tagLength++;
			tagByte = tlvBytesHex[index + 1];
			while (/* tagLength < MAX_TAG_BYTES && */(tagByte & 0x80) == 0x80) {
				tagLength++;
				tagByte = tlvBytesHex[index + tagLength - 1];
			}
			tagBytes = new byte[tagLength];
			System.arraycopy(tlvBytesHex, index, tagBytes, 0, tagBytes.length);
		} else {
			tagBytes = new byte[]{tagByte};
		}
		return new UnpackResult(tagBytes, tagInterpreter.getPackedLength(tagLength));
	}

	private UnpackResult unpackLength(final byte[] tlvData, final int offset) {
		byte[] tlvBytesHex =
				lengthInterpreter.uninterpret(
						tlvData,
						offset,
						tlvData.length >= offset + MAX_LENGTH_BYTES
								? MAX_LENGTH_BYTES : tlvData.length - offset);
		final byte length = tlvBytesHex[0];
		final int lengthLength;
		final byte[] lengthBytes;
		if ((length & 0x80) == 0x80) {
			//Long Form
			int lengthOctetsCount = length & 0x7F;
			lengthLength = lengthOctetsCount + 1;
			lengthBytes = new byte[lengthOctetsCount];
			System.arraycopy(tlvBytesHex, 1, lengthBytes, 0, lengthOctetsCount);
		} else {
			//Short Form
			lengthLength = 1;
			lengthBytes = new byte[]{length};
		}
		return new UnpackResult(lengthBytes, lengthInterpreter.getPackedLength(lengthLength));
	}

	protected byte[] packValue(String tagNameHex, final ISOComponent c) throws ISOException,
			UnknownTagNumberException {
		final int tagNumber = Integer.parseInt(tagNameHex, 16);
		final TLVDataFormat dataFormat = getTagFormatMapper().getFormat(tagNumber);
		String tagValue;
		byte[] packedValue;

		if (c.getComposite() == null) {
			if (c.getValue() instanceof String) {
				tagValue = (String) c.getValue();
				switch (dataFormat) {
					case COMPRESSED_NUMERIC:
						packedValue = new byte[bcdInterpreterRightPaddedF.getPackedLength(tagValue.length())];
						bcdInterpreterRightPaddedF.interpret(tagValue, packedValue, 0);
						break;
					case PACKED_NUMERIC:
					case PACKED_NUMERIC_DATE_YYMMDD:
					case PACKED_NUMERIC_TIME_HHMMSS:
						packedValue = new byte[bcdInterpreterLeftPaddedZero.getPackedLength(tagValue.length())];
						bcdInterpreterLeftPaddedZero.interpret(tagValue, packedValue, 0);
						break;
					case ASCII_NUMERIC:
					case ASCII_ALPHA:
					case ASCII_ALPHA_NUMERIC:
					case ASCII_ALPHA_NUMERIC_SPACE:
					case ASCII_ALPHA_NUMERIC_SPECIAL:
						packedValue = new byte[asciiInterpreter.getPackedLength(tagValue.length())];
						asciiInterpreter.interpret(tagValue, packedValue, 0);
						break;
					case BINARY:
					case PROPRIETARY:
						packedValue = new byte[literalInterpreter.getPackedLength(tagValue.length())];
						literalInterpreter.interpret(tagValue, packedValue, 0);
						break;
					case CONSTRUCTED:
						throw new IllegalArgumentException("CONSTRUCTED tag value should be a composite ISOComponent");
						//packedValue = new byte[literalInterpreter.getPackedLength(tagValue.length())];
						//literalInterpreter.interpret(tagValue, packedValue, 0);
						//break;
					default:
						throw new IllegalArgumentException("Unknown TLVDataFormat: " + dataFormat);
				}
			} else {
				packedValue = c.getBytes();
			}
		} else {
			if (TLVDataFormat.CONSTRUCTED.equals(dataFormat) || TLVDataFormat.PROPRIETARY.equals(dataFormat)) {
				packedValue = pack(c, true, 0, c.getMaxField());
			} else {
				throw new IllegalArgumentException("Composite ISOComponent should be used only for CONSTRUCTED data type");
			}
		}
		return packedValue;
	}

	private ISOComponent unpackValue(String tagNameHex, final byte[] tlvData,
	                                 int subFieldNumber, int dataLength) throws ISOException, UnknownTagNumberException {
		final int tagNumber = Integer.parseInt(tagNameHex, 16);
		final TLVDataFormat dataFormat = getTagFormatMapper().getFormat(tagNumber);
		ISOComponent value;
		String unpackedValue;
		int uninterpretLength;
		switch (dataFormat) {
			case COMPRESSED_NUMERIC:
				uninterpretLength = getUninterpretLength(dataLength, bcdInterpreterRightPaddedF);
				unpackedValue = bcdInterpreterRightPaddedF.uninterpret(tlvData, 0, uninterpretLength);
				if (unpackedValue.length() > 1 && unpackedValue.charAt(unpackedValue.length() - 1) == 'F') {
					unpackedValue = unpackedValue.substring(0, unpackedValue.length() - 1);
				}
				value = new ISOField(subFieldNumber, unpackedValue);
				break;
			case PACKED_NUMERIC:
			case PACKED_NUMERIC_DATE_YYMMDD:
			case PACKED_NUMERIC_TIME_HHMMSS:
				uninterpretLength = getUninterpretLength(dataLength, bcdInterpreterLeftPaddedZero);
				unpackedValue = bcdInterpreterLeftPaddedZero.uninterpret(tlvData, 0, uninterpretLength);

				if (unpackedValue.length() > 1 && unpackedValue.charAt(0) == '0') {
					unpackedValue = unpackedValue.substring(1);
				}
				value = new ISOField(subFieldNumber, unpackedValue);
				break;
			case ASCII_NUMERIC:
			case ASCII_ALPHA:
			case ASCII_ALPHA_NUMERIC:
			case ASCII_ALPHA_NUMERIC_SPACE:
			case ASCII_ALPHA_NUMERIC_SPECIAL:
				uninterpretLength = getUninterpretLength(dataLength, asciiInterpreter);
				unpackedValue = asciiInterpreter.uninterpret(tlvData, 0, uninterpretLength);
				value = new ISOField(subFieldNumber, unpackedValue);
				break;
			case BINARY:
			case PROPRIETARY:
				value = new ISOBinaryField(subFieldNumber, tlvData);
				break;
			case CONSTRUCTED:
				value = new ISOMsg(subFieldNumber);
				unpack(value, tlvData, true);
				break;
			default:
				throw new IllegalArgumentException("Unknown TLVDataFormat: " + dataFormat);
		}
		return value;
	}

	@Override
	public void unpack(ISOComponent m, InputStream in) throws IOException, ISOException {
		throw new IllegalStateException(
				"Call to unpack(ISOComponent m, InputStream in) was not expected.");
	}

	private int getUninterpretLength(int length, BinaryInterpreter interpreter) {
		int lengthAdjusted = length + length % 2;
		return length * (lengthAdjusted / interpreter.getPackedLength(lengthAdjusted));
	}

	private int getUninterpretLength(int length, Interpreter interpreter) {
		int lengthAdjusted = length + length % 2;
		return length * (lengthAdjusted / interpreter.getPackedLength(lengthAdjusted));
	}

	private class UnpackResult {

		private final byte[] value;
		private final int consumed;

		private UnpackResult(final byte[] value, final int consumed) {
			this.value = value;
			this.consumed = consumed;
		}
	}

}
